Israeli navy attacks Hamas base as tanks line up along Gaza border

Israeli navy commandos clashed with Hamas gunmen during a raid on the coast of the Gaza Strip on Sunday, while the army moved more tanks and troops along the border with the Palestinian territory.

The Israeli platoon was attacking a site in northern Gaza used to launch long-range rockets when it came under fire, a military statement said. The commandos returned fire and managed to hit the launch site, the statement said, adding that four soldiers were lightly wounded in the clash.

Hamas said its fighters had fired at the Israeli force offshore, preventing them from landing.

This is the first such gunfight of a six-day Israeli offensive on the territory aimed at stopping Palestinian rocket fire.

Israel says preparations are under way for a possible ground incursion, with tanks and artillery massed along the border and some 33,000 reservists mobilised out of 40,000 approved by the cabinet.

The Israeli army said it was sending messages to residents of northern Gaza "urging them to leave their homes for their own safety."

Yet most attacks so far have so far been from the air, hitting some 1,200 targets in the territory.

FRANCE 24's Irris Makler reports from Jerusalem

FRANCE 24's Jerusalem correspondent Irris Makler says the latest developments do not necessarily indicate an imminent ground assault. "It is not clear to me from listening to Israeli military analysts and the prime minister that this is what is in the offing," she said Sunday morning.

She noted that despite troop movements towards the Gaza border, the numbers did not appear consistent with plans for a full-on invasion.

"There are now Arab mediators coming forth – Qatar is involved, Egypt is going to come back into it. I think that this may in fact be the storm before the ceasefire rather than before the ground offensive," Makler added.

Speaking from Gaza City Sunday morning, FRANCE 24's reporter Gallagher Fenwick said Israel's military campaign had taken a "new dimension" in the northern part of the Palestinian enclave overnight.

"It sounded very much like carpet bombing of entire neighbourhoods, creating scenes of panic with tens of thousands of people trying to flee as fast as possible to reach the United Nations court in downtown Gaza, which has been opened to them," Fenwick said.

Meanshile, the Islamist group Hamas, which dominates Gaza, has fired hundreds of rockets into Israel, striking deeper in the country than ever before.

"This morning we saw a range of rocket fly from the south up towards the centre and sirens were heard at the international airport," FRANCE 24's Makler reported.

Saturday bloodiest day this week

The cross-border violence shows no signs of abating despite mounting international pressure on both sides to end the violence.

The world has implored Israel and Hamas to end hostilities as the toll from Israeli air strikes rose and Gaza militants fired more rocket salvos, but both sides have rejected a truce.

Saturday was the bloodiest day since the conflict erupted on Tuesday, claiming 56 Palestinian lives including a two-year-old child and a 73-year-old woman.

FRANCE 24's Gallagher Fenwick reports from Gaza

FRANCE 24's Fenwick said the death toll compiled by the Palestinian health ministry so far this week was risen 165, including 18 members of an extended family killed in an air raid targeting Hamas's chief of police, who is himself in critical condition.

Sirens went off throughout the night in Israel, sending residents running for safe rooms and bomb shelters.

On Saturday, the UN Security Council unanimously urged Israel and Hamas to respect "international humanitarian laws" and stop the loss of life.

The foreign ministers of Britain, France, Germany and the United States are due to discuss how to achieve a truce when they meet in Vienna on Sunday.

The Italian foreign minister is due to visit the region next week and a spokesman for the Egyptian government said it was in touch with both sides in the conflict, but this falls short of Egyptian engagement to mediate between Israel and the Palestinians in previous flare-ups.

Collateral damage

Israel says Hamas puts innocent Gazans in harm's way by placing weaponry and gunmen in residential areas. A senior Israeli military officer said aircraft had aborted "hundreds" of strikes to avoid collateral damage and that targets bombed were meant to impact Hamas fire capacity.

No Israeli has been killed by the cascade of Hamas rockets, many of which were shot down above Israeli towns by Iron Dome, a partly US-funded interceptor system. Israel rushed an eighth Iron Dome into service on Saturday to counter stronger-than-expected rocket fire from Gaza.

Fire was also exchanged across Israel's northern border.

Rockets fired late on Saturday from Lebanon hit Israel, and the military said it responded with artillery fire at the source of the launch.

Southern Lebanon is a stronghold of Hezbollah, a Shiite Muslim group that battled Israel seven years ago and is engaged in Syria's civil war in support of President Bashar al-Assad; but there are also Palestinian groups in the same area.

Hamas claimed responsibility for the rocket fire from Lebanon, though it was unclear what kind of influence or presence the Islamist group had there.